Cable television systems typically include a head end section that receives satellite signals and demodulates the signals to baseband. The baseband signal is then converted to an optical signal for transmission from the head end section, such as over fiber optic cable. Cable systems also include one or more nodes for converting optical signals to a radio frequency (RF) signal for further transmission along branches of the system that can include coaxial cable rather than fiber optic cable. Taps are situated along the coaxial cable to tap off signals to subscriber premises.
As the cable signal is routed farther from the head end section, the signal is attenuated, and signal levels of higher frequencies are attenuated more rapidly than signal levels of lower frequencies. Amplifiers within the cable television system are used to compensate for attenuation of the signal levels. However, even after amplification, the higher frequencies are at lower levels than the lower frequencies. These uneven, attenuated signal levels are also seen at the subscriber premises since the cable taps merely pass the incoming signal along to subscriber drops. As a result, the higher frequency signals in particular may have levels that are low enough to cause erroneous operation of subscriber equipment.
Thus, what is needed is a way to compensate for attenuated higher frequency signals in a cable television system.